Mass-density of the M-dwarf population of sub-Neptunes, using the same sample as in Fig. 8, adapted from (Luque & Pallé 2022). TOI-912 b and TOI-521 b are labelled and highlighted with diamonds, and the additional THIRSTEE planets are represented with stars. Planets are divided into two populations according to their density, assuming a density gap at 0.65 ρ_⊕,s (dotted blue line), which according to Luque & Pallé (2022) divides the population of rocky planets (brown points) from a volatile (or gas-) enriched population (blue points).